1. Field of the Invention
The present invention relates to a condensed heterocyclic compound and a psychopharmaceutical composition containing the same.
The condensed heterocyclic compounds and salts thereof according to the present invention show activities specific to the .sigma.-receptor, and therefore, are effective as remedies for treating psychoneurosis.
2. Description of the Related Art
The principal conventionally developed remedies for treating psychosis are D.sub.2 -receptor antagonists such as butyrophenone derivatives represented by Haloperidol, phenothiazine, and thioxanthine, owing to the presence of dopamine in the brain.
Nevertheless, many cases have been known which cannot be improved by the use of these D.sub.2 -receptor antagonists, and it is known that the use thereof is accompanied by side-effects such as extrapyramidal tract disorders. Accordingly, there is a need for the development of a specific remedy for treating psychosis, which is not accompanied by side-effects.
In this connection, it recently has been proved that the .sigma.-receptor, which is a subtype of the opioid receptor, is closely involved in the development of various symptoms of psychosis, and remedies have been developed for treating psychosis based on the .sigma.-receptor antagonism, as represented by Rimcazole and BMY 14802 having the following structures, respectively. ##STR3##
Nevertheless, the antipsychotic effect of these Rimicazole and BMY 14802 is inferior to those of existing remedies such as Haloperidol, and as a cause thereof, it is considered that the .sigma.-receptor antagonism thereof is inferior to those of existing remedies such as Haloperidol.